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DALI information

1

DALI information

1.1

DALI standard overview

DALI is an international standard (IEC 62386) lighting control system that provides a single

interface for electronic control gear (light sources) and devices (lighting controllers).

The DALI standard enables dimmable ballasts, transformers, relay modules, emergency

fittings and controllers from different manufacturers to be mixed and matched into a single

control system. A DALI system provides designers, installers, building owners, facility

managers and end-users with a powerful and flexible digital lighting system, with security of

supply from many sources.

The DALI standard is overseen by the “AG-DALI” activity group, which comprises

engineers, manufacturers and institutions working in the field of digital lamp/ lighting control.

More information about the DALI standard can be found in the following documents:

•

IEC 62386

•

NEMA STANDARD 243-2004

The following sections provide an overview of the DALI standard. They describe the basic

principles of the DALI interface.

Note:

To better understand the STM8L DALI slave library, knowledge of the DALI interface

specification is essential. This document does not provide a description of this specification.

1.1.1

DALI purpose and properties

The DALI protocol was designed to control modern light sources using a computer.

Functions include:

•

Dimming

•

ON/OFF switching

•

Grouping lights to a common control

•

Scene storage and selection

The DALI design properties include:

•

Simple wiring using standard electrical installation cables

•

No special wiring topology (as with electrical power cables)

•

Simple installation with cable polarity independence

•

Automated light source addressing

•

Low cost microcontrollers on the light source side minimize the cost of the light source

•

A simple protocol to control light dimming and switching.

1.1.2

DALI physical layer

The DALI interface consists of a physical layer from two wires. This is a simple installation

for which the polarity is independent.